1. Field of the Invention
The present invention generally relates to endoscopic instruments, and is particularly related to surgical tools and procedures which can be used for the release of the transverse carpal ligament, as well as in other applications.
2. Background Description
Examples of surgical tools which are useful for inspecting and manipulating tissues (e.g., cutting of the transverse carpal ligament) in a body cavity are described in U.S. Pat. No. 4,962,770 to Agee, U.S. Pat. No. 4,963,147 to Agee, U.S. Pat. No. 5,089,000 to Agee, and U.S. Pat. No. 5,306,284 to Agee, each of which are herein incorporated by reference. The Agee patents show a probe which houses both a lens system and a selectively deployable blade. The lens system is used to illuminate and image tissue located above an opening in a top surface area of the probe near the probe's distal end. A pistol grip is provided which allows a surgeon to selectively deploy a blade out of the opening in the top surface once the probe is in the desired location. Preferably, the blade is deployed along a path that is close to perpendicular to the probe. The surgeon can then view the blade cutting the transverse carpal ligament for example, while the surgeon moves the probe backwards. This is done by observing the image on a display of the tissue located above the opening in the top surface of the probe. The Agee device allows dividing the flexor retinaculum, thereby releasing the carpal tunnel, while the optical system enables continuous observation of the cutting blade within the field of view above the opening in the probe.
The use of endoscopic instruments for the release of the transverse carpal ligament is a well-established surgical procedure. The devices consist of a cutting assembly for the dissection on the ligament and an endoscope with a camera system for visualization. All of the existing systems use a single edged blade for dissecting the ligament in either a distal to proximal motion or a proximal to distal motion. They also utilize rod lens endoscope technology that makes the instrumentation bulky and the endoscopes fragile. There is room for improvement both in performance and ease of use of the instrumentation to make the surgical procedure simpler and safer.